TY - JOUR
T1 - High molecular weight kininogen binds to laminin--characterization and kinetic analysis
AU - Schousboe, Inger
AU - Nystrøm, Birthe
N1 - Keywords: Calcium; Cells, Cultured; Extracellular Matrix; Fibronectins; Humans; Kinetics; Kininogen, High-Molecular-Weight; Laminin; Protein Binding; Zinc
PY - 2009
Y1 - 2009
N2 - High molecular weight kininogen (HK) is an abundant plasma protein that plays a central role for the function of the kallikrein/kinin/kininogen system. Thus, cleavage of HK by kallikrein liberates bradykinin, which stimulates vascular repair and a two-chain protein, activated HK (HKa), which induces apoptosis in proliferating endothelial cells. The localization of these events remains obscure, although the basement membrane may be of importance. Analyzing the interaction between HK and HKa and selected basement membrane proteins, we observed that they bound to the major noncollageneous proteins laminin, but not to vitronectin or fibronectin coated on microtiter plates. The binding to laminin was Zn2+ independent. However, at low but not at high concentrations of albumin, Zn2+ increased the affinity for the binding by abolishing an inhibitory effect of Ca2+. Recombinant human kininostatin encompassing the amino acid sequence, Arg439-Ser532 but not the endothelial cell binding peptide sequence (His479-His498; HKH20) within kininostatin inhibited the binding of HKa to laminin. This established that the amino acid sequence Arg439-Lys478 in domain 5 of HK is of importance for its binding to laminin. Extensive proteolytic cleavage of HK and HKa with kallikrein abolished the binding to laminin, releasing a 12 kDa anti-kininostatin reacting peptide. On the basis of these results, we propose that the binding of HK to laminin is a primary event, which secures proper localization of the cleavage products for subsequent interaction with the endothelium to promote inflammatory and pro- and anti-angiogenic activities.
AB - High molecular weight kininogen (HK) is an abundant plasma protein that plays a central role for the function of the kallikrein/kinin/kininogen system. Thus, cleavage of HK by kallikrein liberates bradykinin, which stimulates vascular repair and a two-chain protein, activated HK (HKa), which induces apoptosis in proliferating endothelial cells. The localization of these events remains obscure, although the basement membrane may be of importance. Analyzing the interaction between HK and HKa and selected basement membrane proteins, we observed that they bound to the major noncollageneous proteins laminin, but not to vitronectin or fibronectin coated on microtiter plates. The binding to laminin was Zn2+ independent. However, at low but not at high concentrations of albumin, Zn2+ increased the affinity for the binding by abolishing an inhibitory effect of Ca2+. Recombinant human kininostatin encompassing the amino acid sequence, Arg439-Ser532 but not the endothelial cell binding peptide sequence (His479-His498; HKH20) within kininostatin inhibited the binding of HKa to laminin. This established that the amino acid sequence Arg439-Lys478 in domain 5 of HK is of importance for its binding to laminin. Extensive proteolytic cleavage of HK and HKa with kallikrein abolished the binding to laminin, releasing a 12 kDa anti-kininostatin reacting peptide. On the basis of these results, we propose that the binding of HK to laminin is a primary event, which secures proper localization of the cleavage products for subsequent interaction with the endothelium to promote inflammatory and pro- and anti-angiogenic activities.
U2 - 10.1111/j.1742-4658.2009.07218.x
DO - 10.1111/j.1742-4658.2009.07218.x
M3 - Journal article
C2 - 19691495
SN - 1742-464X
VL - 276
SP - 5228
EP - 5238
JO - F E B S Journal
JF - F E B S Journal
IS - 18
ER -